Plant growth regulants

ABSTRACT

THE INVENTION RELATES TO COMPOUNDS OF THE FORMULA:   (R,(X)N-PHENYL)-CH2-CH(-CL)-C*N   WHEREIN R REPRESENTS AN ALKYL GROUP, X IS A HALOGEN ATOM AND N IS FROM 1 TO 3 INCLUSIVE, THE SAID COMPOUNDS ENTERING INTO COMPOSITIONS FOR REGULATING PLANT GROWTH.

United States Patent 01 hoe 3,671,217 Patented June 20, 1972 rm. (:1. Aoln 9/20 US. Cl. 71-105 12 Claims ABSTRACT OF THE DISCLOSURE The invention relates to compounds of the formula:

2 om-onoi-on wherein R represents an alkyl group, X is a halogen atom and n is from 1 to 3 inclusive, the said compounds entering into compositions for regulating plant growth.

This invention relates to novel substituted B-chloro-,3- cyauoethyl-benzenes, to a process for their production and to their use as agents for regulating plant growth.

According to the present invention we provide compounds of the formula:

R 1 a" \2 om-onol-on in which R represents an alkyl group, X represents a halogen atom and n is 1, 2 or 3. Preferably R represents an alkyl group having 1 to 3 carbon atoms. X is preferably chlorine. Especially preferred compounds are those in which R occupies the ortho position with respect to the fl-chloro-fi-cyanoethyl group i.e. the 1-position of the Formula I, n is l and the halogen X occupied the 4- or 6-position of Formula I; also those in which R is in the l-position, It is 2 and the halogen atoms X are in the positions 3 and 4, 4 and 5 or 4 and 6 of the Formula I. Further preferred compounds of Formula I are those in which R is in the l-position, n is 3 and the halogen atoms X are in the positions 3, 4 and 6 of Formula 1.

Examples of preferred compounds of the Formula I in lude:

2- (p-chloro-fi-cyanoethyl)-6-chlorotoluene 2- S-chloro-B-cyanoethyl) -4-chlorotoluene 2-(p-chloro-B-cyanoethyl-4-chloro-l-ethylbenzene Z-( S-chloIo-fi-cyanoethyI)-4,6-dichlorotoluene 2-(fl-chloro-fi-cyanoethyl)-3,4,6-trich1orotoluene The process for their preparation comprises diazotising an amine of the formula:

with nitrous acid at 0 C. in a hydrochloric acid medium, and reacting the resulting diazonium chloride with acrylonitrile in the presence of a catalytic amount of cupric chloride, preferably at ambient temperature, for example 15 to 25 C. or more especially 20 to 25 C. Usually the amount of cupric chloride present will be in the range of 25 to 35 g. of cupric chloride dihydrate per mole of the diazonium chloride.

NH, 5, 6, N 0] +CHz=CH-CN r CuCla CHr-CHCl-CN 'iNiI PREPARATIVE EXAMPLE (1) 137.4 g. (1 mol) of 6-chloro-ortho-toluidine base were dissolved in a mixture containing 300 ml. of concentrated hydrochloric acid and 400 ml. of water.

After cooling to 0 C., g. of sodium nitrite (in 50% aqueous solution) were added rapidly. The temperature was kept below 5 C. during the addition.

(2) 60 g. of acrylonitrile were dissolved in 500 ml. of acetone. The previously prepared diazonium chloride solution was added to it with stirring, and also 25 g. of hydrated cupric chloride CuCl .2H O.

The mixture was stirred for one hour at 15 to 20 C. and then left to stand for 20 hours at 25 C. The reaction was accompanied by the liberation of nitrogen; the 2-(13- chloro-B-cyanoethyl)-6'chlorotoluene formed separated out as an oil, which was separated from the aqueous phase and then diluted with chloroform.

The solution in chloroform was washed with water until free of acidity and then dried by shaking with anhydrous calcium chloride. Finally, the solvent was evaporated.

The residue was vacuum distilled at -130 C./ 0.5 mm.

The resulting product containedv 33.10% of chlorine (theoretical percentage 3 3.14%

The other compounds of the Formula I may be prepared similarly.

The products according to this invention may be used in the form of an aqueous emulsion prepared by dis- 0 solving in an appropriate solvent such as acetone, alcohols, benzene, xylene or mixtures of the latter, and containing ionic and non-ionic surface active agents.

The following composition may be cited as an example of an emulsifiable solution:

250 g. of 2-(fi-chloro-p-cyanoethyl) 6-chlorotoluene 30 g. of surface-active agent (e.g. a mixture of a sulfated fatty alcohol and a polyoxyethylenic derivative of an alkylphenol).

300 g. of n-butyl alcohol made up to 1 kg. with xylene.

The products according to this invention may also be prepared for use in any other forms, for example in the form of wettable powders with an appropriate solid mineral carrier and appropriate surface-active agents.

The following composition may be cited as an example of formulation in the form of a wettable powder:

10% by weight of 2-(fl-chloro-B-cyanoethyl)-6-chlorotoluene.

3% by weight of surface-active agents (e.g. Na alkylbenzenesulfcnates) 3% by weight of dispersing agent (e.g. Na lignosulfonates) 84% by weight of mineral charge (e.g. clay).

The (fl-chloro-p-cyanoethyl)-benzenes according to this invention have a different growth-regulating action on plants to that of products such as (B-chloroethyD-trimethylammonium chloride, or N-dimethylaminosuccinamic acid, which are known to be agents inhibiting plant growth. This difference in action is shown by a substantial difference in the heights and behaviour of plants treated with the different compounds.

Table I shows the results of glasshouse trials with various plants.

These trials involve the application of Z-(fi-chloro-B- cyanoethyl)-6-chlorotoluene; a comparison was made, for the same doses, with known agents for inhibiting plant growth.

The treatment consisted in spraying the leaves. The doses applied are shown in percentages by weight of active substance in emulsion.

-In each case the measurements are related to a control (untreated plant) to which an arbitrary value of 100 has been given. The average of three repetitions is recorded.

The products used are indicated in Table I by the The results of Table I show that the action of 2-(13- chloro-p-cyanoethyl)-6-chlorotoluene on the growth of various plants is more effective than that of known products in this field. This action is proportional to the dose 5 of active substance used.

Table II shows that treatment of salvias with an emulsion containing Z-(fl-chloro-fl cyanoethyl)-6-chlorotoluene in a low concentration causes a considerable growth of the stalk.

To obtain a similar effect with N-dimethylaminosuccinamic acid, which is known to act on plant growth, doses 5 to 10 times as high have been necessary. The effect obtained, however, is still not so marked as when 2-(fi-chloro fi-cyanooethyl)-6-chlorotoluene is used.

The salvias were treated by spraying the leaves. The

doses are shown as percentages by weight of active substance in emulsion.

The measurements are related in each case to a co-ntrol (untreated plant) to which an arbitrary value of 1 has been given. The average of several repetitions has been recorded 54 days after treatment.

TABLE II.-GLAS1S\HOU.SE TRIAL ON SALVIAS (Trial 6) Concentration of active Height ofsubstance, Product used percent Plant Stalk A: 2-(fi-chloro-fl-cyanoethyl)-6-chlorotoluene B: N-dimethylaminosuccinamic acid The (fi-chloro-fl-cyanoethyl)-benzenes according to this invention have an effect on plant geotropism.

This effect is illustrated by trial 7 below, carried out in the glasshouse by the application of Z-(B-chloro-flcyanoethyl)-6-chlorotoluene to Pelargonium.

Thirteen days after the treatment by spraying with an emulsion containing 0.5% of active substance the angle formed by the vertical stal k and the petiole was following symbols: m s d, A: 2-(fl-chloro-p-cyanoethyl)-6-chlorotoluene TRIAL 7 B: N-dimethylaminosuccinamic acid A l measured (3; (p hloroethyl)-tr1methylammOn1um chloride Control 40 5' control. Treated plant 63 0' TABLE I.GLASSHOUSE TRIALS Concentra- Interval tlon of between active treatment Height Product substance, and Trial Plant used percent measurement plant number Solarium Zycopersicum L (tomatoes) A 100 B 77 1 O 62 Vivia am: L (beans) A 57 2 C 58 Apium graveolens L (celery) 100 A 26 3 O Pelaraomum pellatum L (geranium) 100 C 88 Solanum lycopersicum L (tomatoes) 100 A 0 025 55 days 38 A 0.0125 55 days 59 6 A 0.00625 55 days 71 The object of Table III is to show the elfect on the TABLE III Concentra- Number oftion of active Average substance, growth Leaves Fruit set Product used percent of tree per tree per tree Control. 38. 3 40. 3 0.05 37.0 33.6 18. 6 0.05 38. 0 30.0 0

NOTE A=Z-(B-chloro-flcyanoethyl)-6-ch1orotoluene; C (fl-ehloroethyD- trimethylammonium chloride.

Table IV shows the yields per hectare of sugar-beet after treatment at the height of growth with emulsions of 2-(fi-chloro-fi-cyanoethyl)-6-chlorotoluene. The yields are expressed in kg. per hectare; the average of four repetitions is given.

The doses applied are expressed in percentages by weight of active substance in the emulsion in the knowledge that 1,000 litres of this emulsion are used per hectare. Every other trial comprised two treatments, the first in May and the second 21 days after the first.

The measurements were taken at harvest.

TABLE IV Concentration of active Number of Weight in kg.

11 stance treatments hectare Control 77. 680 0.1 1 76. 880 0.1. 2 76. 520 0.05 1 86. 480 .05- 2 78. 320 0.02 1 91. 120 0.025 2 80. 720 At lower concentrations Value reduced to that of control.

The measurements were taken at harvest.

TABLE V Concentration of active Weight in substance, kg. per Beet percent hectare Control 124. 000 Treated 0. 1 157. 000

Analysis of the variance shows that this result is very significant.

Comparative tests of the influence on plant growth resulting from the application of various (B-chloro-fl-cyanoethyl) benzenes according to this invention are illustrated in Table VI.

This shows for test various products the efiects on the growth of tomatoes resulting from the application of emulsions containing 0.025% of active substance.

For each test the height of the plants is measured and the internodes are counted. The results constitute an average of several repetitions.

The measurements were taken 40 days after treatment.

TABLE VI Average Average height of number plant in oi inter- Products cm. nodes Control 40. 3 12 2-(fi-chloro-B-cyanoethyl) -6-chlorotoluene 9. 6 Z-(fl-chloro-B-cyanoethyl)-4=chlorotoluene 22. 3 10 Z-(fl-chloro-B-cyanoethyl)-4-ohloro-1-ethy1benzene. 32. 6 11. 6 2-( B-chloro-fl-cyanoethyl)+6-dichlorotoluene. 28. 3 11 2-(B-chloro-Bcyanoethyl)-3,4,0-trieh1orotoluene 24. 3 10. 6

We have also found that the following substituted (/3- chloro-B-cyanoethyl)-benzenes, in which the substituents on the benzene nucleons do not occupy the especially preferred positions stipulated above, have a destructive action on plants (tomatoes) as a result of the application of emulsions containing 0.025% of active substance, in particular:

2- B-chloro-fl-cyanoethyl -5,6-dichlorotoluenc 2- (fl-chloro-fl-cyanoethyl -3,5-dichlorotoluene 4- (,B-chloro-B-cyanoethyl) -2,6-dichlorotoluene 4- (it-chloro-fl-cyanoethyl) -2,5-dichlorotoluene 4- (B-chloro-B-cyanoethyl -2,3 -dichlorotoluene 4- (B-chloro-fl-cyanoethyl) -2,3,6-trichlorotoluene 4- (B-chloro-B-oyanoethyl -3-chlorol-ethylbenzene.

What we claim is:

1. A method for regulating plant growth comprising applying to the plant an effective amount of compound of the formula wherein R is an alkyl group of l to 3 carbon atoms, n is 1 to 3 and X is chlorine which is situated:

for n=1: in the 4 or 6 position;

for n=2: in 3 and 4 or 4 and 5 or 4 and 6 positions,

respectively; and

for n=3: in the 3, 4 and 6 positions.

2. A method in accordance with claim 1 wherein R is methyl or ethyl and chlorine is situated in the 4 and 6 positions when n=2.

3. A method in accordance with claim 1 wherein said compound is applied to the plants in admixture with a liquid or solid carrier.

4. A method in accordance with claim 1 wherein said compound is 2-(-chloro-fl-cyanoethyl)-6-chlorotoluene.

5. A method in accordance with claim 1 wherein said compound is 2-(fl-chloro-B-cyanoethyl)-4-chlorotoluene.

6. A method in accordance with claim 1 wherein said compound is 2-(fi-chloro-fi-cyanoethyl)-4-chloro-1-ethylbenzene.

7. A method in accordance with claim 1 wherein said compound is 2-(fi-chloro-fl-cyanoethyl)-4,6-dichlorotoluene.

8. A method in accordance with claim 1 wherein said compound is 2 (p-chloro-fl-cyanoethyl)-3,4,6-trichlorotoluene.

9. Compositions for regulating plant growth comprising an effective amount of compound of the formula and a liquid or solid carrier.

10. A composition in accordance with claim 9 which includes a surface active agent in sufficient amount for emulsifying said compound.

11. A composition in accordance with claim 9 wherein said composition is wetable powder containing surface active agent and solid carrier.

12. A composition in accordance with claim 9 wherein said composition is emulsifiable liquid containing surface active agent and organic solvent in which said compound is dissolved.

References Cited UNITED STATES PATENTS 3,285,729 11/1966 Weil 71---126 X 3,331,865 7/1967 Weil 71105 X OTHER REFERENCES Meerwein, J. Prakt. Chem. 152 (1939).

JAMES O. THOMAS, JR., Primary Examiner US. Cl. X.R. 

